%0 Journal Article
%A Zhong, Z.
%A Xu, P. X.
%A Kelly, P. J.
%T Polarity-induced oxygen vacancies at LaAlO3/SrTiO3 interfaces
%J Physical review / B
%V 82
%N 16
%@ 1098-0121
%C College Park, Md.
%I APS
%M PreJuSER-12051
%P 165127
%D 2010
%Z This work was supported by "NanoNed," a nanotechnology program of the Dutch Ministry of Economic Affairs and by EC under Contract No. IST-033749 DynaMax. The use of supercomputer facilities was sponsored by the "Stichting Nationale Computer Faciliteiten" (NCF) which is financially supported by the "Nederlandse Organisatie voor Weten-schappelijk Onderzoek" (NWO).
%X Using first-principles density-functional-theory calculations, we find a strong position and thickness dependence of the formation energy of oxygen vacancies in LaAlO3 vertical bar SrTiO3 (LAO vertical bar STO) multilayers and interpret this with an analytical capacitor model. Oxygen vacancies are preferentially formed at p-type SrO vertical bar AlO2 rather than at n-type LaO vertical bar TiO2 interfaces; the excess electrons introduced by the oxygen vacancies reduce their energy by moving to the n-type interface. This asymmetric behavior makes an important contribution to the conducting (insulating) nature of n-type (p-type) interfaces while providing a natural explanation for the failure to detect evidence for the polar catastrophe in the form of core level shifts.
%K J (WoSType)
%F PUB:(DE-HGF)16
%9 Journal Article
%U <Go to ISI:>//WOS:000283578100004
%R 10.1103/PhysRevB.82.165127
%U https://juser.fz-juelich.de/record/12051